Bubbling Over
by bravevulnerability
Summary: "I was thinking, we should start a new tradition," he muses, flipping open one of the cardboard flaps. "For every time we save each other's life. You know, since it's becoming quite a habit for us." Inspired by events from 8x03, PhDead.


**A/N:** **Set shortly after 2x18, Boom. During Beckett's brief stay in the Castle household.**

 **For Alex.**

* * *

It's still awkward, inserting her key into his door and stepping inside his home unannounced. She's only been living here for three days and Castle has been working nonstop to ensure her comfort, to make her feel like she's more than a guest. Like she belongs. And he hasn't exactly failed, always welcoming her with a warm smile or a hot meal or both. Usually both.

Three days, but it's already begun to feel like more, as if this odd living arrangement is already turning into something she could consider a new normal. As if making breakfast in his kitchen and drinking cocoa with his daughter, watching a movie on his couch with him before bed and discussing cases and the headlines in the Ledger over morning coffee, could constitute as part of her daily routine.

As if she _could_ belong here.

Kate nudges the door shut with her foot, shaking her head over the ridiculous (and potentially catastrophic) workings of her mind. She's being stupid, overly emotional, and a little too soft towards him since he presented her with her father's restored watch yesterday. Since he met her at the front door later that night with a cup of hot cocoa, his daughter's recipe, and braved a kiss to her cheek before murmuring how glad he was that she was okay against her skin. Since she had stood alone in the middle of his kitchen, the heat of his lips searing along her cheekbone, long after he had retreated to his bedroom, ignoring the incredulous urge to follow after him. Reaffirm life.

She doesn't belong here, with him, with his daughter and his mother, with a real family. And she can't allow herself to forget that. This is just temporary. Just a friend helping out a friend whose home was just blown up until she can find a place of her own for the time being. Nothing more.

"Beckett!" Kate startles, nearly drops the single key - that she refuses to attach to her key ring of others - to the floor at the shout of Castle's voice bellowing through the loft, the trot of his footsteps approaching. As if her week hasn't been hard enough, now he was going to give her a heart attack. "You're home!"

 _Home_? What? No-

Castle jogs up to her with an eager expression spilling over his face, exuberance a brilliant sapphire illuminating his eyes. "Guess what came in the mail today?"

"Castle-"

"Never mind, I'll show you," he quips, snagging hold of her wrist and dragging her towards his office, barely giving her a chance to lower the messenger bag from her shoulder, to step out of her heels.

"Better be damn good," she growls under her breath, allowing this man-child she's living with to draw her into his study, where an unopened package sits waiting on his desk.

Castle releases her wrist to retrieve the small box, the packing tape already slit, and Beckett crosses her arms, arches her brow at him, awaiting the prologue to this opening that she knows he's dying to begin.

"I was thinking, we should start a new tradition," he muses, flipping open one of the cardboard flaps. "For every time we save each other's life. You know, since it's becoming quite a habit for us."

Her lips twitch without her consent, enough encouragement for Castle, and he digs into the pool of packing peanuts, withdraws a rectangular, mahogany box with an elegant design on the top and polished gold hinges.

"What did you have in mind?" she asks to fill the silence as he drops the packing box, using his freed hand to open the wooden container balanced atop his palm, revealing a trio of expensive looking cigars. "Castle, I don't smoke," she hedges, eyeing him warily as he plucks two of the cigars from the wooden box, holding one out to her in offering. "And neither do you."

The corners of Castle's mouth quirk. "Who said anything about smoking?"

He deposits the cigar box to the edge of his desk while her lips part with confusion, but then he's blowing on the cigar, producing a string of bubbles that fill the air and pop along her cheeks, float around her shoulders. Kate sputters when another pops on her nose and steals the second cigar from his fingers, puffing her cheeks and producing a swarm of bubbles in retaliation.

Rick releases a laugh, loud and hearty as he backs away from her, not relenting in his bubble assault, though. He spews more bubbles at her, prances away as she chases after him, doing the exact same and having too much fun racing around his office to acknowledge the childish behavior she's indulging, embracing.

"I surrender! I surrender!" he cries once pieces of his hair are wet and sticking up at odd angles from the liquid soap, his shirt dotted with the evidence of their battle.

Kate huffs out a final blow into her pipe, clutching it with her teeth, lips split too wide in a grin to curl around the mouthpiece properly. Castle stumbles backwards in a halfhearted attempt at escape the onslaught and she catches the exact moment the heel of his shoe snares in the edge of the rug, lurching forward to snag him by the hand, but it's too late. He goes down, hard on his ass while his back slams into the wall of books behind him, and inadvertently brings her to her knees with him.

"Oh, I think I broke something," Castle groans, his head thumping back against the bookshelf as he winces, dropping his bubble cigar to rub at one of his knees while Beckett waits for the reverberating ache elicited from their descent to the hardwood floor to disappear from hers.

It's only once her kneecaps have stopped stinging, her bones no longer vibrating with the impact, that she notices the precarious position they've landed in - her hands clutching his shoulders for balance, her knees straddling his thighs, her chest only a breath away from touching his.

And oh, this is bad, so bad, but he's blinking past his own aches and pains, staring up at her with those brilliant blue eyes alight with the happiness he provided them both, the beautiful sound of his laughter still echoing through her head.

"Beckett?" he states, tilting his head at her in bemusement, sudden concern bubbling in his gaze. "Are you hurt?"

He can be a man-child, he can be petulant and immature, but he can also be sweet and breathtakingly thoughtful. Fixing her father's watch because he had seen the devastation that had claimed her face when she had accepted her loss, opening his home to her so she could have a safe place to stay while her life was in danger and her own home in shambles, buying fake cigars that produce bubbles and innocent fun to make her smile. Asking first if she was hurt instead of teasing her mercilessly over the fact that she was an inch away from sitting in his lap.

"Kate?"

His jaw is sticky when she plants her hands there, the soapy residue of the bubbles clinging to her palms as she leans forward to press a kiss to Castle's lips. His mouth is warm, incredibly soft and lovely, parting with a gasp beneath hers. His body has gone completely still, his hands frozen in a hover near her waist, and Beckett uses the moment of surprise to fit her lips to his with a little more finesse, deepening the tentative meeting of mouths and humming at the soft pressure, the pleasant heat when her tongue touches his bottom lip and the taste of bubbles she encounters.

"Why are you laughing?" he mumbles into her mouth, squeezing her hipbones. She isn't sure when his hands made their way to her waist, but his palms are broad, his fingers thick and encompassing, and she's not quite sure what they're doing, what kind of mess she's making, but she gives in and sinks down into his lap.

Castle's fingers bruise her waist, fisting there as she leans in further before attempting to relax, to embrace her into the warm cove of his body.

"You taste like soap," she chuckles, nipping at his upper lip with her teeth, smirking at his scoff of indignation.

"So do you," he huffs, his fingers teasing at the waistband of her jeans, the hem of one of the few blouses she still owns that doesn't reek of smoke and explosives, and her body involuntarily arches forward at the graze of his fingertips along the small of her back.

"You like it," she mumbles, grateful when the words come out smooth rather than breathless.

She can still recall the memory of him favoring a lollipop from one of the many Czech shops they had visited during an investigation only a few months ago, the day before the book party where he had stolen her heart with a dedication and then ignited it with an argument moments later, and it has another laugh fluttering up her throat.

 _Kinda tastes like soap. I like it._

"Beckett, laughing at a guy you're making out with is not a very encouraging sign," he grumbles and she shakes her head at him, ready to inform him that they are _not_ making out, when the click of heels echoes in the doorway, snaps her from the figurative bubble she managed to fall into with him.

"What on earth is... oh," Martha appraises the two of them with a brow that hitches to her hairline, a grand smile spreading across her lips and a pleased glimmer settling in her eyes. "Sorry to interrupt."

"Martha," Kate stammers, because somehow his mother manages to always show up at the most inopportune times since she's been here. "You weren't - we were just-"

"Having a bubble war," Castle finishes for her, retrieving his cigar from the floor and puffing out a large bubble.

"Richard, really? This is how you choose to impress a woman?" Martha sighs, tilting her head up to the heavens in exasperation.

"It worked, didn't it?" He shrugs, directing his attention back to Beckett and arching his brow in question, Martha turning expectant eyes on her as well, but Kate ignores them both, scrambles to rise from his lap.

"Whatever you say, kiddos." Martha waves them off with another sigh, but her eyes are sparking with mischief when she catches Kate's gaze for a second time. "I was just dropping by to-"

"Dropping by?" Castle repeats, grunting as he follows Beckett into a standing position, his knees popping with the effort. "I wasn't aware you'd ever left."

Martha rolls her eyes at her son, sweeping the skirt of her shimmering emerald dress out as if to prove a point. "Darling, you knew I had left a large majority of my things here. I have only returned for the necessity of my favorite cocktail dress for a night on the town with Chet. I'll be going now, you two have fun with your... bubbles."

The curl of Martha's lips has Kate's cheeks flushing crimson, but the approving glance his mother shoots over her shoulder before she departs eases some of the heat from her flesh, offers her a hint of courage she didn't know she needed.

"Sorry about that," Castle murmurs, rubbing at the back of his neck with his hand. "Didn't mean to embarrass you."

"Who said you embarrassed me?" she answers, flexing her soap stained fingers and inhaling a steadying breath through her nose before drifting back towards him, eyeing his mouth before meeting his gaze. "I'm the one who kissed you."

"But I started the bubble war-"

"Am I complaining?" she cuts in, reaching forward to hook her fingers in the belt loops of his jeans. She likes him in jeans, the comfortable kind that are faded and worn with use, likes him in the soft blue sweater he's wearing now that is reserved for lounging at home. "After these last few days, it felt good to have fun," she confesses, reeling him in by the loop of fabric she has hold of and keeping her gaze low, hidden from him by her lashes. "But now, I'm in need of a shower. And maybe... a different kind of fun."

The immediate understanding that ripples across his face is almost comical, but he doesn't allow her the chance to laugh at his expense yet again, palms rising to cradle her face as his fingers glide and tangle in her hair just before he drapes his mouth over hers, eradicates the lingering soapy taste with the confident stroke of his tongue.

She can't help moaning, savoring the unique flavor of coffee and spice, of mint and something that is solely Richard Castle filling her senses while he walks her backwards, through his open bedroom doorway and towards an adjoining bathroom that smells of his aftershave.

"You're sure about this?" he pants, his breath hot and fanning out across her skin. "Because this - I don't want a fling, Kate. I want..."

She can barely catch her own breath, but the heaving of her chest quiets, her ears straining, eager to hear the rest of his sentence. Her heels give her an advantage in height as it is, but she lifts on her toes despite the added help, nudges his nose with the tip of hers in encouragement.

"What do you want?"

"You," he admits on a sigh that sounds so relieved, as if the confession has been a long kept secret finally allowed free. "A real chance with you."

That should scare her, shouldn't it? The idea of pursuing anything with Richard Castle has always sent her backpedaling, mentally compiling a list of reasons why they would never work, why he would hurt her or she would overwhelm him, but standing in his bathroom now, with his eyes hopeful and the newfound addiction of his mouth so close, all of those reasons why they would be destined to fall apart fade away.

She wants him too.

Kate snakes her arms around his neck, submerges her fingers in the so soft hair at the base of his skull, and seals a kiss to his mouth like a promise.

She is under no illusions that a relationship with him will be easy, that they'll fail to wound each other to some capacity, but if the bombing of her apartment has taught her anything, it's that life is short. Too short to work towards being ready to open her eyes to how much he cares for her, as Shaw had mentioned, too short to waste time wondering when the opportunity to know is standing right in front of her, kissing her back with a passion that robs her lungs of air and weakens her knees.

"Can this be part of that new tradition for saving each other's lives that I mentioned?" Castle hums against her lips, unbuttoning her shirt and setting fire to each new strip of bare skin he touches. Always touching things.

He guides her backwards, into the gorgeous walk in shower, helping her shed the rest of her clothes while she makes quick work of his. A pile of fabric forms on the floor, her slacks tangling with his jeans, her sweater bunched with his, her bra snared in his boxers. The water cuts on and he shields her from the initial burst of cold until the steam starts to rise and she allows him to draw her into the heated spray.

"Mm, I was hoping we'd be indulging in this kind of celebration a little more often than that," she challenges, her hands roaming his slick back, relishing in the warmth of his flesh, the contraction of his muscles beneath her fingers as he backs her into the tile wall. Her leg lifts on its own accord, twining around his thigh, desperate to urge him closer, but Castle is already hoisting her up, groaning at the wet slide of her skin against his. Kate bites her lip at the wondrous onslaught of sensation, catches a glimpse of the bubbles racing from their bodies to decorate the drain and holds tighter to his frame, dusts her lips along his ear. "Saving lives and bubble wars no longer necessary to have this."

* * *

Based on a prompt from the castlefanficprompts page on tumblr (and Alex's fantastic tags that were added to said prompt):

 _Beckett instead of Alexis in the bubble blowing cigar scene._


End file.
